The present invention relates to a wiper blade for motor vehicle windshield wiper systems.
In systems for wiping especially the windshield of motor vehicles, certain difficulties arise at high travel speeds, because then the contact pressure of the wiper blade against the window is reduced, with increasing travel speed, by the relative wind striking the wiper blade, and as a result the wiping quality, at least in certain regions of the window, no longer meets the demands made of it. At lower travel speeds, on the other hand, an increased contact pressure would lead to undesirably high and disadvantageous friction between the wiper strip of the wiper blade and the window.
In a known wiper system (European Patent Disclosure EP 0 398 376 B1), a wind deflector strip has been screwed to the wiper blade, extending downward toward the window from the load bearing frame--that is, disposed in suspended fashion; this wind deflector strip, with a wind baffle oriented toward the relative wind, covers substantial portions of the wiper blade. The relative wind striking the oblique wind baffle and/or the negative pressure that builds up behind the wind deflector strip in the region of the wiper blade, are intended especially at high travel speeds to increase the contact pressure of the wiper blade against the window. However, such a suspended disposition of the wind deflector strip, in certain cases--for instance given a special pivotable connection of the wiper blade to a drive wiper arm or where there are relatively short radii of curvature in spherically curved windows--can be problematic. Difficulties can also arise if the wiper system is provided with a device that relieves the wiper blade, in its parking position, from the contact pressure that is required during operation. In such cases, an upright disposition of the wind deflector strip can prove expedient.
In a known wiper system (German Utility Model G 78 26 802.7), the wind deflector strip is mounted on the top of the wiper arm that guides the wiper blade.